Margaret Hassan, also known as “Madam Margaret”, was an Irish aid worker who had worked in Iraq for many years until she was abducted and murdered by unidentified kidnappers in Iraq in 2004, at the age of 59. Her remains have never been recovered.

She was born Margaret Fitzsimons in Dalkey, Co Dublin, to parents Peter and Mary Fitzsimons. However, soon after the end of World War II her family moved to London, where she spent most of her early life and where her younger siblings were born. At the age of twenty-seven, she married Tahseen Ali Hassan, a twenty-nine-year-old Iraqi studying engineering in the United Kingdom. She moved to Iraq with him in 1972, when she began work with the British Council of Baghdad, teaching English. Eventually she learned Arabic and became an Iraqi citizen, as was required of foreigners under Saddam Hussein’s government.

She remained a Roman Catholic throughout her life and never converted to Islam as was widely reported after her death. A requiem Mass was held for her, after her death was confirmed, at Westminster Cathedral by Cardinal Cormac Murphy-O’Connor.

In early 2016, an ISIS prisoner stunned interrogators by claiming to have witnessed the final hours of a murdered British aid worker whose body has never been found or killers brought to justice. Margaret Hassan was director of the humanitarian group Care International in Iraq when she was taken hostage in Baghdad in October 2004. She was twice paraded before the cameras to beg for help before being shot dead on video by masked gunmen three weeks later. No group has claimed responsibility and a combination of missed opportunities, bungled police work and judicial corruption has meant her murderers have evaded justice.

But a surprise confession by a militant brought in for questioning over his links to ISIS may hold the key to finally locating her body and finding those responsible. Mustafa Amer, 23, described in shocking detail how he witnessed Mrs Hassan’s final moments when he was just a boy, around nine years old.

He told how she had been abducted by a Sunni criminal gang with insurgent and political links who were now fighting for ISIS or had links to the terror group. He kept talking about a ‘British Margaret’ and it took some time before it dawned on the interrogator who he was referring to.

Ali al-Sudani, a Colonel in the Iraqi military who questioned him in Tikrit, said: ‘He knew everything: who kidnapped her, where she was held, who killed her and where she is buried.’ But two weeks ago Amer was freed by a court on the basis of forged documents and Col al-Sudani says the authorities have done little to arrest her killers or find her grave.

He said: ‘I have no idea why arrests have not yet occurred. We have all the necessary information. ‘My commanders keep telling me it is a matter of timing. What are they waiting for? ‘Perhaps they are scared or distracted by other things. Or perhaps they have forgotten about Margaret Hassan.’

Mrs Hassan was one of the highest-profile figures to fall victim to the wave of kidnappings which swept Iraq after the 2003 US-led invasion. The Dublin-born Roman Catholic, who had joint British, Iraqi and Irish nationality, was married to Tahseen Ali and had lived in Iraq for 30 years.

In 2009, Ali Lutfi Jassar, 36, a Sunni, was given a life sentence at Baghdad’s Central Criminal Court for his part in her murder. He had been arrested by Iraqi and US forces in 2008 after contacting the British Embassy in Baghdad and attempting to extort $1 million in return for leading them to Mrs Hassan’s body. Jassar, an architect from Baghdad, denied the charges but was convicted after a one-day trial. He was due to appear in court in Baghdad the following year for a retrial, but escaped.

The only other person to face justice was Mustafa Mohammed Salman al-Jabouri, who was given a life sentence in June 2006 after being convicted of aiding and abetting the abductors. His sentence was later reduced on appeal and he was released in 2008.

Mrs Hassan’s family have spent the last 12 years trying to discover where her remains are so she can be brought back to Britain. Speaking in 2009, her sister, Deirdre Fitzsimons, said: ‘We want to ensure she gets buried with the respect she deserves because she has not been treated with respect. My sister was a Catholic and it would be her wish to have a proper Christian burial.

‘However much she loved Iraq, she always wanted to be buried in this country. That is what we want to do for her.’